Closed-hopper sand-blast.



G. F." STEEDMAN. CLOSED HOPPIBR SAND BLAST. APPLmATLoN FILED JUNE 2, 1910.

Patented 1360.27, 19M).

2 SHEETS-amm' 1v,

G. E. s.frEEmn ..N.` CLOSED HOPPBR SAND BLAST.

APPLIOATION FILED .TUNE 2, 1910,

Patented Dec.27, 1910.

2 BHHETB-BHEBT 2.

GEORGE F. STEEDMAN,'OF STIIOUIS, MISSOURI, ASSIGNOR T0 CURTIS & COMPANY MANUFACTURING COMPANY, 0F WELLSTON, MISSOURI, A CORPORATION OF MIS- .CLOSED-SHOPPER SAND-BLAST.

Specicationof Letters Patent.

Patented Dee. 2a, 191e.

Apication filed .Tune 2, 1910.7 Serial No. 564,595.

To all whom it may concern:

Be it known that I, GEORGE F. S'rEEDMAN, a citizen of the United States, residing at St. lLouis, Missouri, have invented a certainl new and useful Improvement in Closed- Hopper Sand-Blasts, of which the following is a full, clear, and exact description, such as will enable ot-hers skilled in the art to which it appertains to make and use the same.

This invention relatesto sand blast apparatus, and particularly to closed hopper sand blasts, namely, -sand blasts of that type in which the sand in the supply hopper is under air pressure. i

One object of my invention is to provide a closed hop er sand blast apparatus whichA is so designed) that the flow of air and sand to the blast tool or nozzlecan be stopped and started instantly without varying or changing the osition of the valve that governs the supp y of compressed air to the sand hopper and mixing chamber, thereby effecting va great saving in the consumption of sand and air, and also eliminating the loss of time caused by exhausting the air from the sand hopper as was heretofore necessary when the blast was cut off.

Another object is to provide a sand blast apparatus which is so designed that the sand hopper can be cleaned out quickly in case damp sand becomes clogged in the discharge opening of the hopper.

Another object is to; provide a sand blastapparatus comprising few parts and de-v signed in such a manner that the parts which are subjected to the greatest wear can be renewed easily. And still another object is to provideA a sand blast apparatus that comprlses as an integral part thereof 'means for removing dust, pebbles and foreign matter from the sand `that is fed to the supply hoper.

ther objects and desirable features of /my invention will-be hereinafter pointed out.

Figure 1 is an elevational view partly in vertical section. of a sand blast apparatus constructed in accordance with my invention; Fig.v 2 is'an enlarged vertical sectional view of the mixing chamber. and the lower portion of the sand hopper; Fig. 3 is a vertical sectional view taken on approximately the line 3 3' of Fig.` 2; F 4 is a top plan view of the parts shown in Fig. 2, a portion of said View being in horizontal section taken on approximatelythe line 4 4 of Fig. 2; Fig. 5 is an enlarged detail view, partly 4in section, of the shut-oli' valve; Fig. 6 is a 4detail sectional view 'of the clean-out valve, said view being taken on approximately the line 6 6 of Fig. 4; Fig. 7 is a top plan view of the mixing chamber, said V-view being taken on approximately the line 7-7 of Fig. 2; and F ig.4 8 is a view of a slightly vmodified form4 of operating mechamsm vfor the shut-olf valve.

Referring to the drawings which illustrate the preferred form of my invention, A designates the closed sand supply hopper .which is provided at its upper end with a filling opening 1 which is 'normally closed by a valve 2, and at its lower end with 'a discharge'o eni'ng 3 through which the vHows 'into t e' mixing chamber B.

A water separator C of any preferred design is preferably arranged between the sand hopper and the compressed air supply pipe 4 so as to remove as much moisture as possible from the air before it enters the supply hopper and the mixing chamber, the compressed air being introduced into the hopper and into 4the mixin chamber by means of a conduit 5 leading om the upper end lof the water separator to the mixing chamber, as shown in Fig. 1, and provided with a branch 5ar that is tapped into'thesand supply hopper adjacent the upper end thereof.

A three-way valve D is larranged in the' conduit 5 between the branch 5a thereof and the water separator so as Yto permit the -sand and air to the blast tool or nozzle 8 isv connected to a sleeve 9 that is tapped into one end of the mixin chamber, as shown in Fig. 2, and a shut-o valve E is arranged in the'mixingI chamber so as to enablethe flow Aof sand and air through the hose 7 'toy sand air to exhaust from the hopperand from .i

be stopped and started instantly at the will mof the operator. The shutoff valve herein ljshown is of the piston or plunger type', and

consists of a plunger reciprocatingly mounted in a stutlingfbox ll 11i one end of the mixingchamber and provided at its mner end with a head 12 to which a soft rub- 5. ber washer 13 is connected by means of a nut 14 mounted on a screw-threaded extension 10*l on said plunger that passes" through the washer, as shown in Fi 5. A 'cross-piece 15,'which is arranged in t e mixing chamber,

10 as shown in Fig. 2, forms a guide for the plunger 10 and also acts as a stop that limits the movement of said plunger in one direc tion, the plunger being moved longitudinally of the mixing chamber so as to carry 15 the valve E into and out of operative position by means of a 'lever 1G whose lower end is connected to an o erating rod 17 by means of links 18, said r 17 passing through lugs 19 on the outside ofthe mixing chamber B 2Cy and being connected to the rear end of the lplunger l0 by shown in Fig. 7.

When the blast is being used the valve E will occupy the position shown in full lines 1n Fig. 2 so that it will not 'obstruct the stream of sand that is forced into the hose 7 by the pressure in the hopper and in the mixin chamber, but when it is desired to cut o 'the blast the -valve Elie moved in-r wardly into the position shown in'broken lines in Fig. 2 so that the soft rubber part 13 thereof will bear against the inner end of the sleeve 9 and thus positively cut off lthe flow of sand and air to the hose 7 which leads to the blast tool.

I have found that a shut-off valve of the construction above described is very elicient because when it is in its operative position, namely, closing the end of the hose 7 as shown in broken lines in Fig. 2, the ,ressure of the air inthe mixing chamber lio ds it so tightlyagainst the end of the sleeve 9 that an air-tight joint is formed, and when it is in lits ,inoperative position, as shown in full lines in'Fiir. 2, it is located out of the path of travel of t esand which 'lowsfrom the supy ply hopper and is thus not subjected to constant abrasion which would cause it to wear out quickly. l do not wish it to be under- 59 stood, however, that my invention'is limited Y to a sand blast apparatus provided with a shut-olf valve of the exact construction herein shown for various` other types' of valves could be used for cutting oil' the iow Iof sand and air from the mixing chamber.

Iiurtheriiiore, instead of using thc lever 16. as shown in Fig. l., for operating the pliiiiger of the shut-ofi' valve said plunger could be operated by means of ropes or cables 16Jl 69 leading from a point sonic distance trom the apparatus and connected to a T-shaped device 16" whose vertical leg isconni'cted by means o'flinks 18d to the operating rod 17 of the valve plunger. i

A sand blast apparatus ofthe construction means of a crosspiece 20, as

' preferably tapered and the ynecessary to renew .because the continual evase? Vsand h per and mixing chamber, and when Said va e was closed the sand and air would flow from the blast tool for several minutes or until all of the air in the hopper had escaped. Consequently, a large amount of sand and air was wasted every time the blast was cut off, and as it took several minutes for the air tocscape from the, hopper a. great deal of time was wasted during the courseoa day in start-ing and stopping the blast. My improved apparatus overcomes this objectionable feature and enables the sand blast to be' stopped and started in-A stantly at the Will of the o erator so that 11e can turn or shift the Work eing operated on without wasting 'air o-r sand or being annoyed by the continuous action of the blast.

The bottom of the sand supply hopper is discharge openfmg 3 is formed ina plate 21 that is detachably connected by means of screws or other suitable fastening devices 22 to an inverted.pyramidal-shaped casting 23 which forms the extreme lower end of the bottom of the sand hopper.' A vertically disposed pipe 24, which is detacliably connected to the casting 23 and to the mixing chamber B, serves as a conduit for the sandthat flows out of the hopper', and a sliding gate or .valve' 25 is reciprocatingly mounted inra guidewayin' the casting 23 so as to lregulate the flow of sand through the discharge opening 3. The head of said 'sand gate 25 1s n'ovided with an o eniiiof and an o )er-ating` nut or Wheel 26 is mounted on a serene threaded stem 27 on said sand gate so as to.

move it longitudinally ot' the guideway iii which it is mounted and thus cause more or less of the opening in the head thereof to alinc-with the discliaigtl opening 3| of the hopper and the conduit 24. The steth if the sand gato passes through a stiilling-b'ix 2b" Awhich closes the outer end of thc guidcwayo l2.) in the casting in which the sand gateI is mounted, and said guideway is `made large enough to enable the sand gate to be entirely` withdrawn from same when the stuffing-box 28 is removed. acter above described permits the the plate 21 and the pipe 24 to be removed easily and replaced at asmall cost, it being saine causes them to wear out quickly. The water separator C removesqa great .A construction of the char-l sand gate,.

said parts frequently action of the sand Aon deal. of moisture from the' air that is introduced into the hopper but nevertheless there is always4 a certain percentage of moisture remaining in the air that causes the sand to become damp, and frequently this damp sand clogs the discharge opening ot' the hopper. To provide for this condition l have equipped the sand hopper with a cleanout valve .F that closes the outer end of-the discharge pipewhich. is tapped into one side of the casting 23 at the lower end of the hopper, as shown clearly inligs. 4 and 6. The valve F is provided with a soft rubber pad 31 that lits tightly against the end of the pipe 30, and said valve is hingdv or pivot-ally connected at 32 to Ia lug on a collar 33 which is secured to the pipe 30. A yoke 34 is pivotally connected to said collar, and anv adjusting screw 35, vwhich is Amounted in said yoke, operates to hold the .valve F tightly seated.. When the yoke 34 isshifted so as to release the valve F the pressure in the sand hopper will cause said valve to fly' lopen and thus permit the damp sand at the lower end of the hopper to esca e throu h the pipe 30 Ain a few seconds. A ter the amp sand has escaped Athe valve F is closed and t-he yoke 34 is returned to its :formery position so that the 'screw 35 therein will bear against-the valve jand thus' force the soft rubber pad of 'said valve tightly against the end of the pipel 30.

Vis

' sized particles of sand to be separated 'from ing chamber,

The ll-ing'opening 1 at the u per end of the sand hopper is preferably ormed in ai y casting 3 6, andthe valve 2 that normally closes said opening is hinged or pivotally connected at 37 to said casting, said valve being provided with a soft rubber pad that bears against the under side of the casting 36 and thus forms an4 air-tight joint when said valve is closed. A Any suitable means may be provided for retaining the valve 2 in position, such, for example, as an arm 38 on a mnuallybperated rock shaftBS which ex-y tends transversely through'the hopper A, as

shown in Fig. 1. TWhen it is desired to fill the hopper this rock shaft is moved in a direction'to cause the arm 38 to pass out of engagement with thev valve 2 and thus permit said valve to swing downwardly, andwhen said rock shaft. is returned toits former position the arm 38 will engage the valve 2 and move it tightly againstits seat.I A dust-re moving chamber G is arrangedabove the filling opening of the supply hopper, and a jet pipe 39 is arranged at one end of said chamber so as to cause a plurality of jets oft' air to pass longitudinally of said chamber, in the direction indicated by the arrows in Fig. 1 and thus cause the/dust and linderthe stream of sand that flows through the grate-bars 40 of the charging hopper 41 which is arranged above said dustseparatsaid charging vhopper being provided with a screen 42 that prevents gravel and other foreign matter from enterind said hopper when sand is being introduced into saine. This dust-separator and gravel -reinoving mechanism forms an' iiitegral part of the sand blast and it eliminates the possibility of the blast nozzle be-` coming clogged or from discharging particles of sand which are too small to be of any use as a cleaning agent. The member or casting which constitutes this dust-separating chamber G is provided with a Harige 43 thatlitsy in an opening in the casting 36 in the top wall of the sand hopper, and said member is provided at its upper side with ra flange 44 which receives the lower end of the chargin hopper 41,the compressed air be# ing con ucted to the jet pipe 39 by means of a pipe 45 which is tapped into the air supply pipe that leads froni the upper end of the waterseparator.

- Having thus described my invention, what I claim as new and desire to secure by Let-- ters Patent is:

1. A sand blast apparatus, comprising a closed sand hopper whose contents is under fluid pressure, a conduit for pestablishing communication between said hopper and a blast tool, means for supplying fluid underpressure to ysaid conduit so as 4to cause a stream of sand'under pressure to emerge from the blast tool, and means for cutting of the flow of sand and fluid pressure from the blast tool without disturbing or varying the supply of Huid pressure to the san hopper.

2.,A sand blast appara-tus, comprisinga closed hopper or container that is adapted to hold, sand under air pressure, a conduit for conducting a stream of sand from said hopper to a blast tool, means for supplying air under pressure to said conduit, and a shut- 0H valve for starting and'stopping the flow` of sand and air vthrough said conduit.

3. A sand blast apparatus, comprising a closed hopper or container that is adapted tol hold sand, a mixing chamber communicating with the discharge opening in said ghopper,l means for supplying compressed air to .said hopper and tothe mixing chamber, a

conduit "communicating with said mixing chamber for conducting a stream offsand and air to a blast tool, andmeans for stopping andvstarting the flow of sand and air from said mixing chamber to said conduit without disturbing the supply of compressed air that is admitted to said hopper and mixing chamber.-

4. A sand blast apparatus, comprising af closed hopper or container that is adaptedxto aio hold sand, a mixing chamber communicating with the discharge opening in said hopper. I

vmeans for supplying compressed air to said hopper and to said mixingchamber, a conduit communicating with said/mixing cha-mber for conducting a stream of sand and air to a blast tool, and a shut-0H valve under control of the operator for controlling the flow of sand and air that pasfses from said mixing chamber into said`conduit.

5. A sand blast apparatus, comprising a closed hopper or container that is ada ted to hold sand, amixing chamber communicating with the discharge opening in said hopper, means for supp ying compressed air to said. hopper and mixing chamber, a conduit communicating with said mixing chamber for conducting a stream of sand and air to a blast tool, and a shut-olf valve in said mixfor controlling the flow of air' ing chamber and sand from said mixing chamber into said conduit, said shut-olf valve being so desi ned that when it is closed the pressure otg the airin the mixing chamber operates to hold it seated, v I A 6. A sand blast apparatus, comprising a closed hopper o1` container for holding Sand, a mixing chamber communicating with said hopper, means for introducing compressed air into said hopper and mixing chamber, said mixing chamber having a discharge opening through which sand and air Hows, a reciprocating valve arranged iii said mixing chamber for closing said dischar e opening, and manually-operated means' or movposition.

7. In a sand blast apparatus, a mixing ing said valve into operative and inoperative Y chamber provided withv an opening through which sand enters same, and an opening through which compressed air enters, a conduit leading from saidinixing chamber for conducting astreani of sand and air to a Y vthan the gate that passes ytobe blast tool, a shut-olf valve arranged in said mixing chamber intermediate the sand-supply opening and the air-supply opening, and means for moving said valve ii'ito'jclosed position so as to cutoff the escape .find air from the mixing chamber into said conduit. Y

8. In a sand blast apparatus, a sand hopper provided at its lowerend with a member which constitutes a portion of the bottom of the hopper, a gate or valve slidingly mounted in said-member for'controlling the discharge of sand' from the hopper, said member being provided with a guideway'of suiiicient dimensions topermit the sand gate drawn .out of same, a closure for the outer end of said guideway, and a stem on said sand gate of -less cross sectional area through an opening in said closure.

9. In a sand blast apparatus, a sand hopper provided at its lower end with a member which constitutes a portion of the bottom of the hopper, a gate or valve slidingly Vmounted in Said mein charge lof sand from the hopper, s aid inember being provided with a guideway of sufhopper, a removable nected to said of said sand from said r for controlling the dis-` cient dimensions to permit the sand gate to be drawn out of same, a -stuiin -box on said member that closes the outer en -of said guideway, and a stem or lunger on the sand ate of less cross sectiona area than the gate t at passes through said stalling-box.

10. In a sand blast apparatus, a sand hopper provided atl its lower end with a member that constitutes part of the .bottom of the plate detachably connected to said member and-provided with a discharge opening through which the sand passes from the hopper, and a removable sand ate or valve arranged in said member underneath said late or controlling the passage of the san through the discharge opening in said plate.

11. In a sand blast apparatus, a sand hopper provided atits lower end with a member thatconstitutes part of the r'bottom of the hopper, a removable plate detachably conmember and provided with a dischar e openin through which the sand passes rom the gate `or ,controlling valve arranged in said member underneath said, plate, a mixing chamber arranged under the hopper, and va detachable connection between said mixing chamber and the member of the .hopper for establishing communication between said mixing discharge opening of the hopper.

chamber and the opper, a removable sand 12. A sand blast apparatus, comprising a closed hopper that contains sand and air under pressure, said hopper being provided with a feed openin and a clean-out opening, avalve for norma ly closing said clean-out opening and which opens automatically when it is released, and means for holding said valve seated.

13. A sand blast apparatus, com rising a closed hopper or container forhol ing sand and air under a tapered bottom Vin which an opening is formed for permitting the sand to escape from said hopper, a clean-out opening in the tapered bottom'of said hopper of sutiicient dimensions to permit damp or wet sand to beforced thiou h same by the pressure in the hopper, a va ve for said clean-out openin which is adapted to b e opened automatically by the ressure'in said hopper, and means for ho ding said valve seated.

14. A sand blast apparatus, com rising a closed hopper or container for hol in sand and air under pressure, saidhopper avng a tapered bottom in which an opening is formed for permitting the sand to esca e hopper, a clean-out opening in the tapered bottom of fcient' dimensions to permit amp or wet sand to b e forced through same by the pressure in the hopper, a. pivotally mounted valve for said opening which. o ens automatically whenitisreleased, an a device pressure,"said hopper having and air to a blast tool, a shut-o valve eraser holds it seated.

15. Asand blast apparatus, comprising a closed hopper orv container for receiving sand and air under pressure, said hopper having .a tapered bottom in which a discharge opening is formed, a clean-outpipe pojecting outwardly from -the inclined ttom of the hopper, a hinged valve that normally bears against the end of said pipe and which opens automatically when it is released, and a yoke-shaped device mounted on the end of the pipe and provided with an adjusting. screw that bears against said valve and holds it seated. f I

1G. A sand blast apparatus, comprising a closed hopper or container for' receiving sand, a mixing chamber communicating with said hopper, means for introducing air under ressure into said hopper and mixing chamer, a conduit leading from said' mixing chamber for conducting a stream of sand under the control of the operator for starting and stopping the flow of sand and air through saidv conduit, andmeans for regulating the flow of sand from the hopper-into the mix! ing chamber.

l?. A. sand blast apparatus, comprising a closed hopp sand, a mixing chamber communicating with said hopper or receiving sand therefrom., a Water separator, means for causing air under pressure to passthrough said water separator and then into the hop er and into the mixing chamber, a valve indcpendent of Athe filling opening in the hopper for permitting the air to exhaust. from said hopper and mixing chamber, a conduitleading from the mixing chamber for supplying a stream of sand and air to'a blast. tool, and an inde- :cutting oii' .the flow of sand and er or container for receiving pendent valve for governing the lion' of air and sand through said conduit.-

18. A closed hopper sand blast provided with means for regulating the iiow of sand out ot' the sand hopper, said means-consisting of a removable metal plate dctachably connected to the hopper and provided with an aperture and a horizontally disposed gate valve cooperating with said plate, a mixing chamber under said gate valve that is connected to 'the source of compressed air supply, said mixing chamber having an outlet for the combined sand and air stream that flows from the mixing chamber, and a yielding stopper for closing said outlet at will so as to cut oii' the fiow of sand and air from the mixing chamber.

lf). In a closed hopper sand blast. a sand hopper, a mixing chamber connected to the sand hopper and to the source of compressed air supply, a sand Valve in the connection between the mixing chamber and hopper for regulating the flow of sand to the mixing chamber, said mixing chamber having an outlet for the combined stream of air and sand,- a stopper in said mixing chamber for air from the mixing chamber, .said stopper being sodesigned that when it is in an open position it will be out of the path of the sand which escapes from the hopper into the mixing chamber, and a means for operating said sto )per at will. i

n testimony whereof I hereunto aiiix my signature in the presence of two Witnesses, this 28th day ot' May 191.0.

GEURGE l". STEEDMN.

Witnesses 2 JOHN S. Brenna,

E. Ullmann.

ves 

